Detection of stationarity

There are multiple methods that can help us in figuring out whether the data is stationary, listed as follows:

Plotting the data: Having a plot of the data with respect to the time variable can help us to see whether it has got a trend. We know from the definition of stationarity that a trend in the data means that there is no constant mean and variance. Let's do this in Python. For this example, we are using international airline passenger data.